<?php
echo 'This is a test'; // This is a one-line c++ style comment
/* This is a multi line comment
yet another line of comment */
echo 'This is yet another test';
echo 'One Final Test'; # This is a one-line shell-style comment
?>

The "one-line" comment styles only comment to the end of
the line or the current block of PHP code, whichever comes first.
This means that HTML code after // ... ?>
or # ... ?> WILL be printed:
?> breaks out of PHP mode and returns to HTML mode, and
// or # cannot influence that.
If the asp_tags configuration directive
is enabled, it behaves the same with // %> and
# %>.
However, the </script> tag doesn't break out of PHP mode in
a one-line comment.